As financial storms go, the one that brewed in the summer of 2008 was enough to blow any investor off course. But that rough weather seems to have affected asset managers’ performance records very differently.

Some firms, such as Schroders and Henderson Global Investors, have shown steady year-on-year improvement through the crisis. Others, such as RCM, the equities manager owned by Allianz Global Investors, appear to have been declining.

Still others, such as Pimco, also owned by Allianz Global Investors, and Franklin Templeton, took performance hits but have since staged recoveries.

Last week, Financial News put together a table of some of the largest and highest-profile listed asset managers in the industry, ranked by the percentage of their assets that were outperforming benchmarks or peer groups during the three years to June 30.

As a way of gauging each firm’s performance, the measure comes with plenty of caveats and is by no means a perfect indicator. But, as Alan Brown, chief investment officer at Schroders, pointed out: “If you are going to have a single metric this is probably the best one.”

This week, Financial News has turned the clock back to look at how the firms have performed over time, using the percentage figures for the rolling three-year period to each June 30 since 2007. From this picture, some sharp contrasts emerge.

Brown put the variations down to the “binary markets” of recent years. He explained: “During the period of the crisis, in equity markets you basically had two big calls to make.

It was whether you got out of financials at the right time, and whether you were in mining and natural resource companies at the right time. Then, in 2009 we found much more variability between stocks. For a stockpicking house like ours, 2009 was the ideal environment.”

Schroders was unable to provide June 30 figures last week for 2007 and 2008, but has calculated the figure as of December 31 each year going back to at least 2005. Since then, the proportion of assets outperforming their benchmarks over the previous three years has steadily improved each year from 63% to 79%. Its portfolios are primarily in equities.

However, firms with improving records of outperformance may find they have to engage in managing expectations, since the consensus in the industry is that it is only realistic to have around two thirds of funds beating targets at any one time.

RCM, which also specialises in equities, has gone from 80% of funds outperforming benchmarks over the three years to June 2008, to 71% a year later and to 66% at June 30 this year.

Roger Miners, head of business development and client service, said the firm’s management regards both figures as in line with its long-term target, which is 70%. It is the 2008 figure that is the outlier, he explained.

He said: “That year simply happened to be a particularly strong period for us, where a number of our strategies were outperforming all at once. More usually we would expect to have around 70%, and have generally maintained it at this level during the past few years.

“In the crisis period, it was not an environment that was generally suited to fundamental bottom-up stockpickers like us. The big macro calls defined performance. The environment we see going forward is much more attractive.”

Fixed-income markets also faced some clear choices, Brown said, though over a different timeframe. The big call was when not to be in asset-backed securities and the other troubled debt asset classes, and when to get back in.

Pimco’s results illustrate this. It is received wisdom that the bonds investor made the right call on the US housing crisis, but about 12 months too early, and this seems to be borne out in its results.

In June 2007, 83% of Allianz Global Investors’ fixed-income assets – mostly accounted for by Pimco – were ahead of target for the previous three-year period. In 2008 this had fallen to 79%, and in 2009 to 71%. Then, this year, the record showed a striking improvement, to 90%, as the profits from bets placed in preceding years finally came good.

Nevertheless, reducing an entire firm’s record to a single number is an inexact science. Some firms, such as Legg Mason and Franklin Templeton, disclose numbers only for retail and mutual funds. For those firms that also disclose institutional data, these are calculated on a different basis from retail.

But over the crisis period, the problems multiply further, thanks to the corporate change the industry has undergone. A striking example is BlackRock. Its figures for June 2009 and June 2010 relate to two very different businesses, thanks to the inclusion of the old Barclays Global Investors in the second figure.

Though most of BGI’s funds are passive and hence excluded from both figures, the manager did have several hundred billion dollars of active funds, now incorporated into BlackRock’s totals.

A spokeswoman said: “Certain products and strategies were reclassified, making like-for-like performance comparisons less applicable to that of the combined firm. Reclassifying even one large product from one category to another has the potential to make a difference.”

The latest figures for Henderson Global Investors – released last week in its first-half results – present a similar problem, owing to its acquisition of New Star Asset Management.

Andrew Formica, chief executive, said: “Last year’s three-year number did not incorporate the assets we took on after acquiring New Star Asset Management. While we have worked to improve performance at these funds, the three-year records are still below where we would want them to be.”

Its equities and fixed-income businesses showed an improvement in the proportion of outperforming assets from June 2009 to June 2010 of 69% to 72%. So this would likely have been even greater if ex-New Star funds had not been included.